On aircraft and other items requiring a smooth surface finish, filler material may be used to smooth over fasteners or other surface imperfections. The filler material are typically in disk form to fill the heads of the fasteners. These disks may be melted in place using a hot iron at a high temperature. The disks are typically hand-held in place while the disks are melted. Applying the filler material in this manner makes positioning the disks difficult, and also poses a significant risk of burns to the hands, especially when the filler material is applied on vertical and overhead surfaces.